Primary valve for pneumatic musical instruments



B. R. VAN VALKENBURG.

PRIMARY VALVE FOR PNEUMATIC MUSICAL INSTRUMENTS.

APPLICATEON FILED MAR. 8.1916.

1 350, 395, Patented Aug. 24, 1920. I

O O O O r 9 1 9 Fa? .4

J J J J- ll /llll llllllll 'll m fiifa wl m INVENIJOR. zs v Ell/"i fif Foal 0, 1

UNITED STATES BURT R. VAN VALKENBURG, 0F OAKLAND, CALIFORNIA.

Application filed March 8, 1916.

T 0 all whom it may concern Be it known that I, BURT R. VAN VALKEN- none, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Primary Valves for Pneumatic Musical Instruments, of which the following is a specification.

This invention relates to pneumatically operated musical instruments and more particularly to the valve arrangement by which the various pneumatics are thrown into operation for the purpose of moving the action associated with keys of a musical instrument.

The principal object of my invention is to provide an improved valve for the abovementioned purpose, which is quickly responsive to the opening of the holes in the tracker bar.

Another object is to provide a primary and secondary valve system, whereby the former may be made comparatively smaller and the latter large thus giving small air capacity in the primary system while permitting the employment of large openings in the secondary system.

Another object is to provide a primary which is closely connected to the pneumatic of the secondary so that the operation of the latter is in a manner independent of the amount of vacuum carried in the chest.

Still another object of the invention is to provide a valve arrangement, which allows a shallow chest to be used together with a large pneumatic, thereby economizing space and at the same time giving a strong impulse to the action of the musical instrument.

With these and other objects in view my invention consists in the novel construction, combination and arrangement of parts herein illustrated and more specifically pointed out in the appended claims.

Reference being had to the accompanying drawing forming a part of this specification,

Figure 1 is a bottom plan view showing a portion of the valve chest and disposition of the pneumatics for operating the various note sounding mechanisms.

Fig. 2 is a similar view with the lower plate removed.

Fig. 3 is a view in transverse section showing-the details of the primary and secondary valve and the pneumatic associated with Specification of Letters Patent.

PRIMARY VALVE FOR PNEUMATIC MUSICAL INSTRUMENTS.

Patented Aug. 24, 1920.

Serial No. 82,829.

each striking mechanism of the musical instrument.

Referring to corresponding parts in the several views by the same numerals of reference, 1 denotes in general the valve chest which, as shown, consists of an inner member 2 and an outer member 3, between which is a thin layer at of packing material to secure an airtight joint. A vacuum chamber 10 is provided between the members 2 and 3, preferably in the inner face of the outer member 3, and extends throughout the length of the chest, communicating with a suitable exhausting device through the tube 11 which extends therefrom. Attached to the top of the chest are the pneumatics 5, one for each note striking mechanism, and each comprising a. fixed board 6, a movable board 7, connected by the flexible material 8. The board 7 is provided with an extension 9, to which is attached a member 9 connecting the movable side to the striking mechanism of the musical instrument.

Below chamber 10, and separated there from by flexible diaphragms 14, are a plurality of depressions in member 3, forming cells 13, and in the member 2 above the vacuum chamber, cavities are provided alining with cells 13 and having therein the double faced valves 18 and 19. These valves each consist of two disks adjustably mounted on a stem 15, the lower end of which rests on the diaphragm 14:, while the upper end is slidably guided in the hole 22. The upper disk of valve 19 contacts with the top of cavity 16, while the lower disk rests on a ring 17 seated in an annular recess around the cavity at the bottom thereof. In the upper side of the member 2 are two longitudinal slots 20 extending the entire length thereof, these slots being so disposed that a strip 21 is left standing therebetween, thus providing a convenient means in which the upper end of valve stem 15 is slidably mounted. The slots 20 provide passageways under the pneumatics 5 for the entrance of atmospheric pressure into cavities 16, connecting passage ways 24 being provided for this purpose, and cavities 16 are connected to their respective pneumatics through ducts 25.

In the bottom face of member 2 and above the vacuum chamber 10 is a second set of cells 12 separated from the vacuum chamber by flexible diaphragms 26. These cells have ducts 27 extending therefrom,

which are connected by tubes 28 with the openings in the tracker bar. Attached to the underside of each diaphragm 26 is a disk 31 against which abuts a pin 35, located within a passageway 32 which extends to the outside of member 3. Said pin is attached to a flexible strip 34 the ends of which are attached to the outer surface of member 3 in suitable manner, as forinstance by tacks an. These strips are preferably of leather, and are, under normal conditions, held over the outer ends of the passageways 32, thereby normally preventing entrance oi air into said passageways. The lower ends of pins 35 are attached to said strips 34 asstated. The ends of the pins 85 are of substantial diameter to afford ample bearing siu'iace, the intermediate portions of the stems being reduced as indicated at 36 to avoid obstructing the passage of the air. From passageways 32 lateral branches 33 extend to cells 13, and small bleedholes 38 are )rovided from chamber 10 to the cells 12.

The operation of the device is as follows When an opening in the sheet music passes over one of the openings in the tracker bar communicating by tube 28 with a cell 10, atmospheric pressure is admitted into the cell 12, above the diaphragm 26 which having vacuum on the opposite side is pressed downwardly. This action causes disk 31 to close the upper end of passageway 32, and at the same time causes the pin 35 to press the strip 34.- outwardly,whereby atmospheric pressure is admitted beneath said strip into passageway 32 and from said passageway through the lateral passage to the cell 13, beneath diaphragm This cell having vacuum on the upper side, or the diaphragm, the latter is forced upwardly, 6., toward the pneumatic, which action moves the valve 16 in the same direction, thereby seating the upper disk, and unseating the lower disk whereupon the vacuum in chamber 10 will exhaust the pneumatic and cause the connecting member 5) to actuate the corresponding striking mechanism of the musical instrument. As soon as the opening in the perforated paper passes the hole in the tracker bar, the tube 28 and cell 12 are exhausted through the bleedhole 38 connected therewith, equalizing the pressure on both sides of the diaphragm 26 thereby causing the strip 34 to again seal passage way 32. This in turn cuts oil atmospheric pressure, from that portion of cell 13 which is below diaphragm 1-1, and causes said portion to be exhausted through the passageways 33 and 32 so that the pressure on both sides of diaphragm 14 becomes equalized, whereupon disk 19 is pulled downwardly by the suction of the vacuum and seated on the ring 17. This unseats disk 19, and allows the atmospheric pressure to flow in through the slots 20 and passageways 2 past the valve disks 19, and through the duct 25 to the interior of the pneumatic 5, whereupon the latter will expand and all parts then in their normal position. It will be noted that the stem 35 is so supported that no guiding means is required. Should dust, lint, or other foreign particles lodge in the primary valve, causing it to work sluggishly, to leak or to be otherwise defective it is only necessary to disengage one end of strip 34 to enable the operator to remove the valve stem and valve for examination and repair.

WVhile I have shown the preferred construction of my invention it will be understood that changes may be made in minor details of design without departing from the scope of the claims.

\Vhat I claim as new and wish to cover by Letters Patent is 1. A pneumatic action of the character described comprising a valve chest having primary passages, flexible closures for the inlet ends of said passages, tracker bar diaphragms positioned opposite the other ends of said passages, primary valves attached to said diaphragms, stems attached to said flexible closures and positioned to. be en gaged by saidprimary valves, and pneumatic-operative means controlled by said primary valves. r l

2. A pneumatic action 01" the character described comprising a valve chest having primary passages, flexible closures for the inlet ends of said passages, tracker bar diaphragms located above the flexible closures and positioned'opposite to the other ends of said passages, primary valves attached to said diaphragms, stems attached to said flexible closures and interposed between them and said diaphragms, and pneumatic operative means controlled by said primary valves.

8. A pneumatic action oi 'the character described comprising a valve chest having primary passages, flexible closures for the inlet ends of said passages, tracker bar diaphragms positioned opposite the other ends of said passages, primary valves attached to said diaphragms, stems attached to said flexible closures and positioned to be engaged by said primary valves, said closures consisting oi flexible strips attached to the valve chest at both ends, whereby said stems will move in a straight line when said closures are actuated.

In testimony whereof I affix my signature.

BURT R. VAN VALKENBURG. 

